Newcomer is sister of former premier Thaksin Shinawatra, ousted in a 2006 coup

Yingluck Shinawatra insists she "can't do anything special" for her brother

(CNN) -- The decisive victory by Yingluck Shinawatra and her Pheu Thai party was "a very strong punch in the gut" to Thailand's ruling elite and will in fact lend the country some stability for now, said one political observer of Thailand.

The new reality for Thailand is that Yingluck's brother Thaksin, the former prime minister who was ousted in a 2006 coup, remains extremely popular, and that fighting the electoral will would be dangerous, said Roberto Herrera-Lim, a director at Eurasia Group, a political risk research and consulting firm.

In a strong message to those who would consider being a turncoat to Yingluck's party, former Thaksin supporters who had defected in 2007 and enabled Prime Minister Abhisit Vejjajiva's rise to prime minister lost in Sunday elections, Herrera-Lim pointed out.

The ensuing months will also be a time for the military to reassess strategy, to assess whether the pro-Yingluck sentiment is a temporary development or not, he added.

Yingluck's priority in the coming days will be to build a secure coalition -- increasing its number of seats in the lower chamber of parliament from the more than 260 it won to about 300 -- and then identify Cabinet ministers and form the next parliament, Herrera-Lim said.

Thailand picks first female PM

New Thai PM asks for voter patience

New Thai PM: Thaksin case to be reviewed

Gallery: Thailand timeline 2001-2011

The ruling party was swift in acknowledging its loss: Prime Minister Abhisit conceded before Yingluck declared victory. Hours later, Abhisit announced he would resign as leader of the Democrat Party.

Yingluck, whom Thaksin himself had dubbed his "clone," had sent out signals that the election was not about him.

Thaksin now lives in exile and faces a two-year jail sentence at home after being convicted in absentia on a conflict-of-interest charge.

When asked about a potential pardon of her brother in an interview with CNN just before the election, Yingluck said: "I can't do anything special for my brother." Her mandate, she said, would include making sure "every process is followed by the rule of law."

Thaksin also downplayed any immediate return to Thailand. Speaking to reporters in the United Arab Emirates, he said, "Going back home is not a major concern. It's not a top priority. The priority is to bring back reconciliation."

The military had also signaled days before the election that it would not stage a coup in the event of a Pheu Thai win.

"For the moment, everyone is trying to do the right thing to avoid a political conflict," Herrera-Lim said.

That the elections transpired in what appears a free and fair pattern marks a "victory for developing democracies in Asia," said Thitinan Pongsudhirak, director of the Institute of Security and International Studies at Chulalongkorn University in Bangkok.

"The verdict follows similar patterns we've seen in the last decade of Thai elections," he continued. "In 2001, 2005, 2006, 2007 and again in 2011, voter frustration was clear: The majority of voters chose Thaksin's party in all of the elections in the last decade."

Nonetheless, Pongsudhirak noted, Thaksin's Thai Rak Thai party and its successor, People's Power Party, were ultimately dissolved by the courts.

In opinion pieces published before the elections, Pongsudhirak proposed a post-election roadmap for the next three to six months.

Under the grace period, the army chief would remain, the deaths from last year's political protests would be investigated, Thaksin would stay away, key policy fronts would not shift drastically, and a controversial amnesty proposal for those facing charges in the 2006 coup would be put on hold. Furthermore, the anti-Thaksin coalition would have to refrain from protests as in 2008, when Abhisit came to power, Pongsudhirak added.

The main challenge for Yingluck won't be cobbling together a coalition but keeping election promises and meeting the expectations of those who voted for her party, Herrera-Lim said.

Her party's victory at the polls can be attributed not just to the immense popularity of her brother in many parts of Thailand, but also discontent over rising prices -- and with it the Abhisit government, he said.

Any programs involving government handouts -- whether to farmers, the elderly or for schoolchildren -- would carry a price tag; the question is whether such promises can be delivered.

One thing to watch for is Bangkok, which solidly backed the Democrats on Sunday, Herrera-Lim said. "If Bangkok had gone for Thaksin, this would have been a more solid win" for Yingluck, he said.

Should Yingluck's party miscalculate, "Bangkok may once again be at the center of anti-Thaksin protest," he added.